Apparatus for holding packaging bags

ABSTRACT

An apparatus for holding stacks of plastic packaging bags, including a wicket and a securing device for securing the packaging bags to the wicket. The wicket includes a pair of elongated leg members, and a cross-member connecting together the leg members. Each of the leg members has a series of locking portions for selectively locking the securing device to the leg members at pre-determined distances from the cross-member. The securing device includes a pair of securing buttons having a bore sized and shaped to be slidable onto the leg members over the locking portions. The locking portions are pairs of aligned locking tabs shaped to prevent the securing buttons from sliding back off the leg members. A cartridge comprising a plurality of wickets coupled together by break away tabs can be used to automate a bag-stacking operation. The wicket and securing buttons are made to be recycled along with the bags lips left after bags are torn off, reducing waste. The wicket and buttons also provide improved locking of bags, and one wicket is capable of holding varying quantities of bags.

FIELD OF THE INVENTION

The present invention relates to a packaging apparatus, and in particular to apparatus for holding stacks of plastic packaging bags.

BACKGROUND OF THE INVENTION

Packaging bags are used for packaging in a number of industries, including for example food-packaging industries such as the baking industry. A packaging bag is typically made of a thin sheet of a plastic, often polyethylene or polypropylene, which is folded upon itself to form two plies, and is then sealed along the side edges, leaving the remaining end open. Typically, one ply is left longer than the other to define a lip, and a pair of holes is formed in the lip to allow each bag to be secured to other bags. A tear line is also typically formed to allow the lip of the bag to be torn off.

It is desirable that stacks of packaging bags be held together in a flatwise contiguous manner such that an operator of a packaging machine can quickly and easily select one bag from the stack of bags for use in packaging items. One current device for holding stacks of bags together comprises a piece of metal wire, such as a steel wire, bent into a ‘U’ shaped wicket. The holes in the bags are aligned, and the wicket is inserted into the holes. A pair of rubber washers, also known as grommets or discs, having an inside diameter smaller than the diameter of the wire, are placed onto the legs of the wicket to hold the bags in place. The frictional force between the stretched rubber washer and the metal wire wicket keeps the washer in place.

During operation, bags are ripped from the metal wicket along the tear line, leaving the lip of each bag behind on the steel wicket. Once all the bags have been ripped off of the wicket, the entire assembly containing the metal wicket, the bag lips and rubber washers is usually discarded as it is time consuming to remove the washer from the wire for reuse or to recycle the bags lips. Thus, undesirable waste is generated.

The rubber washers or discs used with prior art wickets tend to provide a less than desired gripping force. The rubber washers may not be fitted to the wire properly, and may loosen or fall off the metal wire, resulting in bags that are not properly secured, and which may be lost or impede with a bag-stacking process. Also, it is often difficult to automate the process of using metal wickets to secure stacks of bags. Metal wickets are often individually packaged, and generally must be manually prepared for insertion into a stack of bags. Typically, a more-than-desired level of operator involvement is required.

There is accordingly a need in the art for packaging bag holding apparatus that reduces the amount of waste generated while reliably securing stacks of packaging bags together in a way that can be easily automated.

SUMMARY OF THE INVENTION

The present invention is directed to an apparatus for holding plastic packaging bags, comprising a wicket and a securing device for securing the packaging bags to the wicket. The wicket comprises a pair of elongated leg members, and a cross-member connecting together the leg members. Each leg member comprises a shank extending along a longitudinal axis and having a free end shaped to pass through apertures in the plastic bags. The securing device comprises a pair of securing buttons, each of the securing buttons comprising a button body having a bore extending therethrough, the bore being sized and shaped to allow the button body to be slid onto and along the shank towards the cross-member. The leg members comprise a series of longitudinally spaced locking portions for selectively locking the securing buttons to the leg members at selected distances from the cross-member to secure the stack of bags against the cross-member.

In a preferred embodiment, the shank of the leg members has a generally cross-shaped cross section, defined by pairs of ridge members oriented perpendicularly to each other. The locking portions preferably comprise pairs of aligned locking tabs extending outwardly from at least one of the pairs of ridge members. The locking tabs have a wedge shaped forward portion and a rearward portion having a generally vertical trailing edge to allow sliding in one direction, but to resist sliding in the opposite direction.

The body of each securing button preferably comprises a rigid front body section and a rear body section having a resilient tubular wall. The button body is sized and shaped such that the buttons can be slid onto a wicket leg by deforming or ‘ovalizing’ slightly the region of the bore extending through the rear body section as the button body passes over a locking tab. As the button is pushed over the pair of locking tabs, the forward portion distorts the wall of the narrow portion of the button, forcing it to acquire an ‘oval’ shape such that it can pass over the locking tabs. Once a securing button is mounted on a leg member, a shoulder surface on the button engages with the trailing edges of the locking tabs to prevent the button from being removed from the wicket leg. The button therefore can only travel along the wicket in one direction. The large end of the securing button is sized for engaging and pressing against the plastic bags to secure them to the wicket. Thus, the buttons and locking tabs securely hold the bags in place, and will not loosen or fall off during use.

The wicket and securing buttons are preferably made of a rigid plastic, selected from a material, such as a polyethylene or a polypropylene, which is the same or is compatible with the material the bags are made from such that the wicket and the bags can be recycled together. During operation, individual bags are ripped from the wickets along a tear line to be used for packaging items, leaving behind a bag lip on the wicket. Once all the bags have been ripped from a particular wicket, the entire assembly including wickets, bag lips and securing buttons can be recycled together. Therefore, the amount of undesirable waste is reduced.

The present invention is also directed to a cartridge of wickets comprising a plurality of wickets, in which each wicket in the cartridge is connected to one or more other wickets such that a cartridge can be easily handled as one discrete unit, but which also allows an individual wicket to be easily removed from the cartridge. This may be accomplished by using break-away plastic tabs connecting adjacent wickets together. In some embodiments, the cartridge is formed as a continuous unit using an injection molding process to create the wickets and break-away tabs during one step. The cartridge of wickets is designed to be compatible with an automated or semi-automated bag stacking machine, thus providing for an improved bag-stacking process which reduces undesirable manual labor

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, with reference to the following drawings, in which:

FIG. 1 is a perspective view of packaging bag holding apparatus made in accordance with a preferred embodiment of the invention;

FIG. 2 is a detailed perspective view of a portion of a leg member of the wicket shown in FIG. 1;

FIG. 3 is a sectional view of the leg member of the wicket, taken along line A-A of FIG. 2;

FIG. 4A is a side view of the securing button of the present invention;

FIG. 4B is a perspective view of the securing button shown in FIG. 4A;

FIG. 5 is a sectional side view of the securing button mounted on a leg member of the wicket of the subject invention;

FIG. 6 is an end elevational view of the apparatus of the subject invention shown holding a stack of packaging bags;

FIG. 7 is a perspective view of the subject apparatus shown holding a stack of bags with a number of bags having been removed from the stack;

FIG. 8 is a perspective view of a cartridge of wickets made in accordance with the subject invention;

FIG. 9 is a schematic side view of a bag-stacking machine with a cartridge of wickets made in accordance with the subject invention;

FIGS. 10 a and 10 b are perspective views of a section of a leg member made in accordance with an alternative embodiment of the invention;

FIG. 10 c is a perspective end view of a portion of a leg member made in accordance with an alternative embodiment of the present invention; and

FIG. 11 is a perspective view of an alternative embodiment of the apparatus of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, illustrated therein is apparatus for holding stacks of flexible packaging bags made in accordance with a preferred embodiment of the invention. Packaging bag holding apparatus 10 comprises a wicket 11 and securing device shown generally as 13 for securing plastic bags to wicket 11. Wicket 11 comprises a pair of elongated leg members 12 a, 12 b, and cross-member 14 connecting leg member 12 a, 12 b together in a spaced, parallel relationship. Each of leg members 12 a, 12 b comprises a shank 15 having a free end 20 shaped to pass through apertures in the packaging bags, and a series of longitudinally spaced locking portions 16 spaced along shank 15 at pre-selected distances from cross-member 14.

Securing device 13 comprises a pair of securing buttons 18. Each of securing buttons 18 comprises a button body 19 having a bore 40 extending therethrough sized and shaped to enable button body 19 to be slid along shank 15 and to engage with locking portions 16 so as to secure the stack of bags against cross-member 14.

Shank 15 of leg member 12 a extends along longitudinal axis z and shank 15 of leg member 12 b extends along longitudinal axis z′ that is parallel to axis z and spaced to accommodate the openings of the bags being secured. Each shank 15 preferably has a generally cross-shaped cross-section, as a cross-shaped cross section provides a rigid and strong yet light-weight construction. Free end 20 of shank 15 has a tapered profile to allow leg members 12 a, 12 b to slide easily into apertures in the plastic bags. Locking portions 16 spaced along leg members 12 a, 12 b enable apparatus 10 to secure stacks of bags containing various quantities of bags using the same size wicket 11. The length of shank 15 and the spacing between locking portions 16 are selected to accommodate different quantities of packaging bags as well as bags of various thicknesses, according to standards in the industry, and can be adjusted to meet particular applications.

Wicket 11 and securing buttons 18 are generally made of a rigid material such as a plastic, for example polyethylene or polyethylene, preferably high-density polyethylene. Alternatively, wickets 11 and securing buttons 18 can be made from polyurethane, nylon, other plastics or other suitable material. In the preferred embodiment, wicket 11 and securing buttons 18 are made from the same material as the plastic bags being secured, or a material that is compatible with the bag material so they can be recycled together.

Cross-member 14 preferably comprises a flat slat 23 extending perpendicularly to and rigidly connecting leg members 12 a, 12 b together. Cross-member 14 and leg members 12 a, 12 b are preferably formed as one piece using an injection molding process.

Turning now to FIG. 2, showing a portion of shank 15 of leg member 12 a in greater detail, shank 15 has a cross-shaped cross section, formed by pairs of ridge members 22, 24 extending along longitudinal axis z and orthogonally to each other. With reference to the x-y-z coordinate system shown in FIG. 2, pairs of ridge members 22, 24 comprise a first pair of ridge members 22 extending vertically in the x-direction, and a second pair of ridge members 24 extending horizontally in the y-direction. Each of first ridge members 22 has a longitudinally extending side edge 31 and each of second ridge members 24 has a longitudinally extending side edge 33. Locking portions 16 are shown spaced along pairs of first ridge members 22, although it will be appreciated by those skilled in the art that locking portions 16 would work equally as well if spaced along pairs of second ridge members 24.

Each of locking portions 16 comprises a pair of aligned locking tabs 17 extending outwardly from side edges 31 of first ridge members 22. Each of locking tabs 17 comprises a wedge shaped forward portion 26 and a rearward portion 27. Forward portion 26 comprises an outwardly inclined plane shaped to allow securing buttons 18 to be slid onto and along shank 15 towards cross-member 14. Rearward portion 27 has a flat top surface 28 parallel to side edge 31, and a trailing edge 29 extending perpendicularly to side edge 31. Trailing edge 29 is shaped to engage with securing buttons 18 and thereby prevent securing buttons 18 from sliding back along shank 15 towards free end 20.

Referring now to FIG. 3, the distance between side edges 31 of pairs of vertically extending first ridge members 22 is h, and each of locking tabs 17 extends a distance I away from side edge 31 of one of the pairs of first ridge members 22. The largest cross sectional dimension of shank. 15 is H, the distance between the outside surfaces of aligned pairs of locking tabs 17, where H=h+21. The distance between side edges 33 of horizontally extending pairs of second ridge members 24 is w. Each of first ridge members 22 and second ridge members 24 has a thickness d. Typically, the combined width h of the pair of first ridge members 22 is slightly larger than the combined width w of the pair of second ridge members 24. The relationships between the w, h and H dimensions is such that an object with a circular bore of a diameter close to value of the h dimension will only pass over a pair of locking tabs 17 by deforming slightly or ovalizing the bore into an elliptical shape. The thickness d is chosen to provide shank 15 of leg members 12 a, 12 b with sufficient strength and rigidity to support the secured plastic bags. In the preferred embodiment, w is 4 millimeters, h is 5 millimeters, I is 0.5 millimeters, H is 6 millimeters, and d is 1 millimeters.

Turning now to FIGS. 4A and 4B, button body 19 of securing buttons 18 comprises a disc shaped front section 30 having a wide flat front surface 32 for pressing against the plastic bags, a resilient, tubular rear section 34, and an intermediate tapered section 38 connecting front button section 30 to rear button section 38. Bore 40 of button body 19 comprises a front bore region 42 extending through front button section 30, rear bore region 44 extending through rear button section 34 that is smaller in diameter than front bore region 42, and intermediate tapered bore region 46 extending through intermediate button section 38. Tubular rear button section 34 has a thin resilient wall having a thickness t, the wall defining a shoulder surface 36 shaped for engaging trailing edge 29 of locking tab 17. Wall thickness t is small enough to allow rear bore region 44 to distort or ovalize to slide over locking tabs 17.

Front bore region 42 has a diameter that is larger than H, the largest cross sectional dimension of shank 15, such that front button section 30 can pass freely along shank 15 without being impeded by pairs of locking tabs 17. In the preferred embodiment, front bore region 42 has a diameter around 7 or 8 millimeters.

Rear bore region 44 has a diameter that is large enough to allow rear button section 34 to be slid over pairs of locking tabs 17 on leg member 12 by deforming or ‘ovalizing’, but small enough to permit shoulder surface 36 to butt up against trailing edge 29 of locking tabs 17. Variation in the size of rear bore region 44 is possible by adjusting the wall thickness t of rear button section 34, as a thinner wall thickness t will make it easier to deform rear button section 34. Rear bore region 44 has a diameter typically around h. In the preferred embodiment, rear bore region 44 has a diameter of around 5 millimeters, and wall thickness t of rear portion 34 is about 1.5 millimeters.

Wide flat front surface 32 of front button section 30 is sized sufficiently large relative to the apertures in the plastic bags to engage the plastic bags and prevent them from sliding off of wicket 11 when securing buttons 18 are attached to leg members 12 a, 12 b. Thus, front surface 32 is at least slightly larger than the apertures in the plastic bags into which leg members 12 a, 12 b of wicket 11 are inserted. In the preferred embodiment, large flat surface 32 has a diameter of about one inch or 25.4 millimeters.

FIG. 5 shows a securing button 18 mounted onto leg member 12 a of wicket 11. Securing button 18 is shown having passed over two pairs of locking tabs 17 a, 17 b during mounting by ovalizing at rear button section 34, and rear button section 34 has now returned to its regular shape. Securing button 18 is now adjacent a particular pair of locking tabs 17 b, and the shoulder surface 36 is engaged with trailing edge 29 of locking tabs 17 b such that securing button 18 cannot slide towards the free end 20 of leg member 12 a. Front surface 32 of securing button 18 is in position to engage with a stack of plastic bags (not shown) to hold them in place and prevent them from sliding off of wicket 11.

FIGS. 6 and 7 show apparatus 10 holding a stack of bags 48. Wicket 11 has been inserted into apertures 58 in stack of bags 48, and securing buttons 18 have been mounted onto leg members 12 a, 12 b of wicket 11 to secure stack of bags 48 together. Stack of bags 48 will thus be securely held between cross-member 14 and securing buttons 18.

As shown in FIG. 7, a particular bag 50 can be removed from stack of bags 48 by ripping or tearing bag 50 along tear edge or tear line 52. This ripping action leaves lip portions 54 of the removed bags still attached to wicket 11. Bag lip portions 54 ensure that stack of bags 48 remains securely held by apparatus 10 and will not come loose even though a large number of bags may have been removed.

Turning now to FIG. 8, the present invention is also directed to a wicket cartridge 60 for use in an automatic or semi-automatic bag-stacking machine. Wicket cartridge 60 comprises a plurality of wickets 11 and a series of break-away tabs 62 connecting together adjacent wickets 11. As shown, wicket 11 a is connected to wicket 11 b by break-away tabs 62 a located between cross-member 14 a and cross-member 14 b. It should be appreciated, however, that tabs 62 could be positioned to interconnect different portions of wickets 11 such as leg members 12 in a variety of different ways.

By joining adjacent wickets 11 together, cartridge 60 has sufficient strength to be handled as a unit, allowing cartridge 60 to be easily inserted into an automated or semi-automated bag-stacking machine, while still allowing individual wickets 11 to be easily removed for use. In a preferred embodiment, wicket cartridge 60 can be formed as one piece using an injection molding process. It will be appreciated by those skilled in the art that while ten wickets 11 are shown in cartridge 60, the number of wickets 11 in a particular cartridge can vary according to the particular needs of an application.

FIG. 9 illustrates how wicket cartridge 60 may be utilized in a bag-stacking machine to insert wickets 11 into stacks of bags 48 a, having apertures or holes 58. Wicket cartridge 60 is aligned above stack of bags 48, traveling along conveyor 66, with the edge of cartridge 60 engaged against hard stop 68. Once a particular stack of bags 48 a reaches the appropriate location on conveyor 66, a separator 70 moves downwards, breaking a particular wickets 11 c off of cartridge 60. Wicket 11 c is pushed down through holes 58 in stack of bags 48 a, and into securing buttons 18 positioned below stack of bags 58 to receive leg members 12 of wicket 11 c. Once stack of bags 48 a is secured by wicket 11 c, stack of bags 48 a then continues moving along, and a new stack of bags 48 b moves into position. Separator 70 returns upwards to a reset position, and cartridge 60 moves towards hard stop 68 to occupy the space left vacant by removed wicket 11 c. Additional securing buttons 18 are then positioned to receive leg members 12 of wickets 11. The process for inserting wicket 11 into stack of bags 48 can thus be fully or semi-automated, and the need for manual intervention is reduced.

Referring now to FIGS. 10A and 10B, illustrated therein are alternative embodiments of the leg member of the wicket of the present invention, having shanks with differently shaped cross sections. As shown in FIG. 10A, shank 15 a has a “Y” cross-section, and locking tabs 72 extending outwardly from vertically extending ridge member 73. As shown in FIG. 10B, shank 15 b has 6-pointed star shaped cross-section, and pairs of locking tabs 74 extending outwardly from vertically extending ridge members 75. Other alternative cross-sections for the leg member include a solid circle or square cross-section having protruding locking tabs, a “T” shaped cross section, a 5-pointed star, and others as will be appreciated by those skilled in the art.

FIG. 10 c illustrates a further alternative embodiment of the leg member of the present invention, having shank 15 c with a blunt tip 20 c.

Referring to FIG. 11, illustrated therein is apparatus 10 a, made in accordance with an alternative embodiment of the invention, comprising securing device 13 a and wicket 11. Securing device 13 a comprises a locking plate 21 having a flat front surface 25 and a rear surface 27 and securing buttons 18 a, 18 b extending outwardly from the rear surface 23. Securing buttons 18 a, 18 b are spaced so as to register with spaced leg members 12 a, 12 b, respectively.

It should be apparent to those skilled in the art that the packaging bag holder apparatus of the present invention has a number of advantages over prior art apparatus. By using the same or compatible materials as the plastic bags to make the wicket and the securing buttons, the entire apparatus with bag lips attached thereto can be recycled together once all the bags have been removed. This eliminates the waste that would be generated with some of the prior art wicket apparatus. Further, the securing buttons and locking tabs of the present invention provide a reliable and effective locking means that resists loosening, and holds the stacks of plastic bags firmly in place. The locking tabs spaced at pre-determined distances along the leg members of the wicket allow the same size of wicket to be used to hold different quantities of bags of various thicknesses, according to generally understood standards in the industry. For example, stacks of one hundred bags or five hundred bags can be held on the same sized wicket. The present invention are also highly useful for automating the bag stacking process. Using a cartridge of wickets allows for easy manipulation of a large number of wickets, and lends itself towards a bag-stacking machine using an automated process for stacking bags.

Accordingly, while the invention has been described with regard to preferred embodiments, it should be understood by persons skilled in the art that various modifications may be made thereto without departing from the present invention, the scope of which is defined in the claims appended hereto. 

1. Apparatus for holding a stack of packaging bags, comprising: a) a wicket comprising a pair of elongated leg members and a cross-member connecting the leg members together in a spaced parallel relationship, each of the leg members comprising a shank having a free end shaped to pass through apertures in the packaging bags; and b) a securing device for securing the packaging bags to the wicket, the securing device having a pair of bores extending therethrough, each of the bores being sized to allow the securing device to be slid onto and along the shank of each of the leg members towards the cross-member; c) wherein each of the leg members comprises a series of longitudinally spaced locking portions for selectively locking the securing device to the shank at pre-selected distances from the cross-member so as to secure the stack of bags against the cross-member.
 2. The apparatus of claim 1, wherein the securing device comprises a pair of securing buttons, each of the securing buttons comprising a button body having a bore extending therethrough, the bore being sized to allow the button body to be slid onto and along the shank.
 3. The apparatus of claim 2, wherein each of the locking portions comprises a pair of aligned locking tabs extending outwardly from side edges of the shank, each of the locking tabs having a forward portion shaped to distort the bore of the button body to allow the button body to be pushed over the pair of locking tabs, and a rearward portion having a trailing edge shaped to engage the button body and prevent the button body from sliding back over the pair of locking tabs towards the free end of the shank.
 4. The apparatus of claim 3, wherein the forward portion of each of the locking tabs comprises a wedge shaped portion extending outwardly from one of the side edges of the shank.
 5. The apparatus of claim 4, wherein the trailing edge of the rearward portion of the locking tabs extends generally perpendicularly to one of the side edges of the shank.
 6. The apparatus of claim 5, wherein the button body comprises a rigid front body section having a flat front surface for pressing against the packaging bags, and the bore comprises a front bore region extending through the front body section, the front bore region having a diameter sufficient to allow the button body to pass over the pairs of locking tabs of the leg member.
 7. The apparatus of claim 6, wherein the button body also comprises a rear body section having a resilient tubular wall, and the bore comprises rear bore region extending through the rear body section, the rear bore region having a diameter less than the largest cross sectional dimension of the shank, wherein the tubular wall is sufficiently thin to enable the rear bore region to distort to allow the button body to pass over the pairs of locking tabs.
 8. The apparatus of claim 1, wherein the shank of each of the leg members has a cross-shaped cross section.
 9. The apparatus of claim 8, wherein the shank of each of the leg members comprises a pair of first ridge members and a pair of second ridge members, the pair of second ridge members being oriented perpendicularly to the pair of first ridge members.
 10. The apparatus of claim 9, wherein the locking portions comprise pairs of aligned locking tabs spaced along and extending outwardly from at least one of the pairs of first ridge members or the second ridge members.
 11. The apparatus of claim 1, wherein the wicket and the securing buttons are made from a material compatible, for the purposes of recycling, with the packaging bags.
 12. The apparatus of claim 9, wherein the wicket and the securing buttons are made from a polyethylene plastic.
 13. The apparatus of claim 1, wherein the securing device comprises a locking plate having a flat front surface and a rear surface, and a pair of spaced securing buttons extending outwardly from the rear surface of the locking plate, the securing buttons being spaced so as to register with the pair of leg members.
 14. An apparatus for holding plastic bags, comprising: a) a wicket having a pair of elongated leg members connected together in a spaced parallel relationship, each of the leg members having a free end shaped to pass through an aperture in the packaging bags, wherein each of the leg members comprises a series of longitudinally spaced locking portions located at pre-selected distances along the leg members; and b) a pair of securing buttons for securing the packaging bags to the wicket, each of the securing buttons having a bore sized and shaped to be slid along one of the leg members to secure the packaging bags to the wicket, the locking portion and the bore being shaped to prevent the securing button from sliding back towards the free end of the leg member.
 15. The apparatus of claim 14, comprising a cross-member for connecting together the leg members.
 16. The apparatus of claim 15, also comprising a locking plate, wherein the securing buttons extend outwardly from the locking plate in a spaced relationship so as to register with the leg members.
 17. Apparatus for holding a stack of packaging bags, comprising a wicket having a pair of elongated leg members, and a cross-member rigidly connecting together the leg members in a spaced parallel relationship, each of the leg members having a free end shaped to pass through apertures in the packaging bags, wherein each of the leg members comprises longitudinally extending ridge members, the ridge members comprising a pair of first ridge members and a pair of second ridge members, the pair of second ridge members extending perpendicularly to the pair of first ridge members.
 18. The apparatus of claim 17, also comprising a pair of securing buttons shaped to be slid along the leg members towards the cross-member, wherein the leg members comprise pairs of locking tabs extending outwardly from the side edges of the first ridge members, the locking tabs being shaped to engage with the securing buttons so as to prevent the securing buttons from sliding back towards the free end of the leg members.
 19. Apparatus for use with an automated machine for stacking plastic bags, comprising a cartridge comprising a plurality of wickets, each of the wickets comprising a pair of elongated leg members and a cross-member connecting the leg members together in a spaced parallel relationship, and a plurality of break away tabs connecting adjacent wickets together, the break away tabs being shaped to allow wickets to be separated from each other upon application of a suitable force.
 20. The apparatus of claim 19, wherein the break away tabs connect together the cross-members of the adjacent wickets. 